1) Field of the Invention
The present invention relates to an improved structure of ventilating insole, which is a concave trough with casing is set in the central part of the lower insole, then place a sponge which is trough-shaped in equal thickness and made of elastic and porous materials onto the trough of the lower insole, the casing around trough is glued to an air permeable layer, so that an air chamber can be formed owing to elasticity of sponge, and air permeable layer are respectively set a plurality of air inlet ports at the heel portion and a plurality of air outlet ports at the toe portion, a ventilating insole is then finished.
Such a ventilating insole provides for pumping cool air into the interior of the shoe as a result of the normal walking action, thus, the shoe keep ventilating properly.
2) Description of the Prior Art
Usually, in the warmer and more humid climates, shoes often ventilate insufficiently so that heat and sweat produced while walking are not easy to get rid of. If wearing shoes for a long time, the wearer might feel uncomfortable. It is easy to multiply mildew and get the annoying athlete's foot. Thus, to solve humidity and heat are the important subject for shoemaking industry. At present, there have been some methods to improve ventilation of shoes, for example: insole with ventilating function, U.S. Pat. No. 4,215,492 issued Aug. 5, 1980; U.S. Pat. No. 5,010,661 issued May 30, 1991; U.S. Pat. No. 5,333,397 issued Aug. 2, 1994, above three types of ventilating insole assembled air chamber at the heel portion of the foot with different methods. Furthermore, said ventilating insole set air inlet ports at the heel or the rear edge of the heel portion, and set air outlet ports at the toe portion of the upper insole or the toes of the foot. The continuous stepping up/down in walking can push cool air around the heel portion of the foot into the toe portion of the foot so as to remove humidity and heat around the toe portion of the foot, owing to air chamber making of elastic material. However, such kinds of air chamber are not large enough, so, air content is limited. If intending to enlarge air contents, it has to increase thickness of insole at heel portion, which is not applicable to common shoes. Another example, the shoe ventilating insole in U.S. Pat. No. 4,224,746 issued Sep. 30, 1980; this type of ventilating insole is composed of an air chamber and a support around air chamber. The air chamber is made of a resilient sponge-like material and an impervious plastic film used to wrap sponge-like material, the top of the air chamber contacts foot, air inlet ports is set at the rear edge of the heel portion and air outlet ports is set at the front of the ball portion thereof. Sponge with smaller holes and high density besieged air chamber as a support of air chamber. Air chamber of this type of ventilating insole only occupies partial space of the insole, so, its air content is less; because the air chamber sets air inlet ports at the rear edge of the heel portion, so, when the wearer is walking, if air inlet ports is not covered by heel, the air in air chamber cannot effectively enter into the toes of the foot. Furthermore, the air chamber and the support around air chamber are produced separately with spongy material in different densities, since insoles have different sizes, so, it may increase difficulty to assemble such ventilating insoles.
In referring to above described data, the applicant herein specially puts forward improved method to make light and thin insole with large air contents, higher ventilating efficiency that is applicable to all types of shoes.
Thus, this inventor has finally succeeded in developing this practical “an improved structure of ventilating insole”.